Seal seat construction for a ball valve



A lef-FAw Feb. 1z, 1963 R. P. DUMM SEAL SEAT CONSTRUCTION FOR A BALL VALVE Filed June 26, 1961 SEAL SEAT llfl a. Viaijli) Robert l. Dumm, Long dencia, assigner to l'jaeir'ie Valves, luc., Reach, a1 casper in o Caiiornia This invention relates to a seal seat construction, particularly for a ball valve, and one obiect of my invention is to prevent internal line pressure within the valve from getting behind the plastic seat and extruding or forcing that seat or seal ring out of its metal housing.

Another object of my invention is to provide a novel seal seat construction in which paclrings or (2i-rings are provided in the seal seat, so that the internal pressure with-in the valve will create forces which hold the plastic seal in its metal housing. These packings or G-rings act like a ring `on a piston in an engine, tending to press the seal seat into its housing.

Still another object is to provide a seal seat construction so designed that trapped air behind the seal seat will be eliminated during assembly.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed escription and the appended claims.

In the drawing:

FGURE l is a vertical sectional view of a ball valve embodying my seal seat construction.

FIGURE 2 is a fragmentary horizontal sectional view of the same.

FlGURE 3 is an enlarged fragmentary horizontal sectional view of my seal seat construction.

FIGURE 4 is a fragmentary horizontal sectional view of a modified form of seal seat construction.

Referring more particularly to the drawing, the numeral .l indicates the body of a ball valve7 and `this body includes an intake port 2 and an outlet port The usual pipe line in which a valve is mounted is attached to the ports 2 and 3 in a usual well known manner. A ball 4 is rotatably mounted in the body l, and this ball includes a iluid passage which may rotated into or out of alignment with the ports 2 3, all `of which is usual and well known in a valve of this type. A hub or journal 6 is formed on the upper end of the ball il, and a similar hub or journal 7 is formed on the lower end of the ball. These hubs `are in vertical alignment and are arranged and mounted substantially as shown. A control stem 8 engages the upper hub o for the purpose of rotating the ball il. The stem ti is rotated by a handle 9 attached to the upper end thereof. 'lie stem 3 also extends through a suitable packing gland iti, all of which is usual and well known in the art. The ball ai is engaged on the inlet side 2 by a seal seat assembly il, and on the outlet side by a seal seat assembly l2. "Ehe seal seat assembly il and l2 are substantially identical in construction and, therefore, only one will be described in detail. A metal housing i3 lits within a properly shaped recess 14 in the body l. rihe metal housing i3 is formed with an annular groove l5 in the inner face thereof, and this groove receives an annular seal seat lo. The housing l2 is formed of a suitable metal, while the seal seat lo is preferably formed of a plastic such as Teilen (polytetrafluoroethylene), or a similar or analogous plastic.

(itl

Since valves are frequently subjected to quite high intermal pressures, the iiuid pressures therein will tend to get back of the seal seat, suc-l1 as 16, and. force that seat or extrude out of its internal housing. To prevent this l provide the following structure:

An outer G-ring 17 is seated in the seal seat 16 and engages the outer wall of the groove 15. A second 0` ring i3 is also mounted in the seal seat 16 but on the innermost wall thereof, so that this O-ring engages the innermost wall of the groove l5. The O-rings ll718 act like piston rings in the piston of an internal combustion engine, and any pressure within the valve will be exerted against the small exposed surface of the O-rings lill-Ilia thus exerting a force on the seal seat 16, tending to push the seal seat towards the bottom of the groove id, and will thus Itend 4to hold the seal seat in its houspo prevent 4air from becoming trapped in the bottom of the annular groove l5 when the seal seat 16 is `assembied therein, i pro-vide an air relief structure consisting of one `or more holes i9 which are drilled in the housing towards the edge of the housing opposite the groove 3.5i, and these holes thus will vent any compressed air which might be formed within the groove l5 as the seal seat is assembled in the groove. After the seal seat 3 6 is assembled, and assumes its final or operative posir, the holes is* may be plugged by a threaded plug 52d, or by a plug which is Welded in place, or a similar closure structure.

ln the modication shown in FiGURE 4 the structure of the housing 2l is similar to the housing 13;

also the seal seat 22 is similar in construction to the seal seat llt?. Also the 0rings 23 and 24- `are similar to the O-rings lli-l, previously described, and perform the same function. The modication shown in FIGURE fr relates to the means of preventing air pressure from accumulating back of the seal seat 22 as that seal seat is assembled. In this instance a plurality of horizontal recesses L25 are drilled in the metal housing 2l, and these recesses extend into the groove 26 which receives the seat 22. Due to the enlarged area created by the additional drilled recesses 25 the en-trapped air does not increase in pressure to a substantial amount, or at least not sudicient to push or extrude the seat 22 out of the housing 2l. if desired the housings Ztl or 13 may each be provided with a lip Z7, which is rolled over one edge of the seat lo or 2.2 to assist in holding this seat in its housing, and lalso will assist in preventing the seat from being pushed out of the housing under pressure.

if desired, 4the metal housings i3 or 21 may be provided with an G-ring 2S, which O-ring engages a wall of the recesses li or l2 to pack-off between the body 1 and the housing 13 or 2l, to prevent leakage around the outside of the metal housing.

Having described my invention, I claim:

l. A valve compri-sing a body, said body having an intal-:e and an outlet port therein, a ball rotatably mounted in said body between said intake and outlet ports, a seal seat assembly in said body engageable with the ball, said seal seat assembly comprising a metal housing, said metal housing having a groove formed therein, a sealing ring in said groove, one face of the sealing ring engaging the ball, and packing means positioned between the sealing ring and said metal housing, said packing means 3 being Within said groove in the housing, said housing having a pressure relief vent hole therein to relieve air pressure on assembly of the sealing ring in the housing, and a plug in said vent hole to close the same.

of said groove to span 'the space between the sealing ring and the adjacent wall of the housing, said housing having a pressure relief vent hole therein to relieve air pressure `on assembly of 4the sealing ring in the housing, and a 2. A valve comprising -a body, said body having an 5 plug in said vent hole to close the same.

intake and an outlet port therein, a ball rotatably mounted in said body between said intake and outlet ports, a seal seat assembly in said body engageable with the ball, said lseal seat assembly comprising a metal housing, said metal housing having a groove formed therein, a nonmetallic sea-ling ring positioned in said groove, one face of the sealing ring engaging the ball, packing means mounted on the sealing ring on both of the outer and inner faces thereof, said packing means engaging the adjacent wall References Cited in the le of this patent UNITED STATES PATENTS 10 2,664,267 Ray Dec. 29, 1953 2,839,674 Kaiser Iune 17, 1958 2,950,897 Bryant Aug. 30, 1960 2,963,260 Siravo Dec. 6, 1960 2,963,262 Shafer Dec. 6, 1960 

1. A VALVE COMPRISING A BODY, SAID BODY HAVING AN INTAKE AND AN OUTLET PORT THEREIN, A BALL ROTATABLY MOUNTED IN SAID BODY BETWEEN SAID INTAKE AND OUTLET PORTS, A SEAL SEAT ASSEMBLY IN SAID BODY ENGAGEABLE WITH THE BALL, SAID SEAL SEAT ASSEMBLY COMPRISING A METAL HOUSING, SAID METAL HOUSING HAVING A GROOVE FORMED THEREIN, A SEALING RING IN SAID GROOVE, ONE FACE OF THE SEALING RING ENGAGING THE BALL, AND PACKING MEANS POSITIONED BETWEEN THE SEALING RING AND SAID METAL HOUSING, SAID PACKING MEANS BEING WITHIN SAID GROOVE IN THE HOUSING, SAID HOUSING HAVING A PRESSURE RELIEF VENT HOLE THEREIN TO RELIEVE AIR PRESSURE ON ASSEMBLY OF THE SEALING RING IN THE HOUSING, AND A PLUG IN SAID VENT HOLE TO CLOSE THE SAME. 